PortAudioMBS Windows has a big problem

This is doing my head in. Not so long ago, I used port audio to record my (guitar) input. It would create a nice wavefile, I could replay it back and at any speed. It was great and incredibly useful.
Suddenly, after one compiled and installed version of my app, I found that the wave file, when ran from program files, produces waves with absolutely no data (correct length but no sound). In any other situation, like the build folder or the IDE, it works perfectly. I have tested it at least 50x just today in every possible permutation. It’s not a file permission thing. Any ideas?

Well, details?

Maybe restart your computer and try again?
Do you have version tracking for your changes, just in case you made a recent change in the project, that broke this?